~eliasnaur/gio

ref: 3fc8f55350da880cf7cd5cc802c37f45f304f0bd gio/gpu/internal/rendertest/util_test.go -rw-r--r-- 7.0 KiB
3fc8f553Elias Naur app/internal/wm: [macOS] close display link after window close 5 months ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
// SPDX-License-Identifier: Unlicense OR MIT

package rendertest

import (
	"bytes"
	"flag"
	"fmt"
	"image"
	"image/color"
	"image/draw"
	"image/png"
	"io/ioutil"
	"path/filepath"
	"strconv"
	"testing"

	"golang.org/x/image/colornames"

	"gioui.org/f32"
	"gioui.org/gpu/headless"
	"gioui.org/internal/f32color"
	"gioui.org/op"
	"gioui.org/op/paint"
)

var (
	dumpImages   = flag.Bool("saveimages", false, "save test images")
	squares      paint.ImageOp
	smallSquares paint.ImageOp
)

var (
	red         = f32color.RGBAToNRGBA(colornames.Red)
	green       = f32color.RGBAToNRGBA(colornames.Green)
	blue        = f32color.RGBAToNRGBA(colornames.Blue)
	magenta     = f32color.RGBAToNRGBA(colornames.Magenta)
	black       = f32color.RGBAToNRGBA(colornames.Black)
	white       = f32color.RGBAToNRGBA(colornames.White)
	transparent = color.RGBA{}
)

func init() {
	squares = buildSquares(512)
	smallSquares = buildSquares(50)
}

func buildSquares(size int) paint.ImageOp {
	sub := size / 4
	im := image.NewNRGBA(image.Rect(0, 0, size, size))
	c1, c2 := image.NewUniform(colornames.Green), image.NewUniform(colornames.Blue)
	for r := 0; r < 4; r++ {
		for c := 0; c < 4; c++ {
			c1, c2 = c2, c1
			draw.Draw(im, image.Rect(r*sub, c*sub, r*sub+sub, c*sub+sub), c1, image.Point{}, draw.Over)
		}
		c1, c2 = c2, c1
	}
	return paint.NewImageOp(im)
}

func drawImage(t *testing.T, size int, ops *op.Ops, draw func(o *op.Ops)) (im *image.RGBA, err error) {
	sz := image.Point{X: size, Y: size}
	w := newWindow(t, sz.X, sz.Y)
	draw(ops)
	if err := w.Frame(ops); err != nil {
		return nil, err
	}
	return w.Screenshot()
}

func run(t *testing.T, f func(o *op.Ops), c func(r result)) {
	// draw a few times and check that it is correct each time, to
	// ensure any caching effects still generate the correct images.
	var img *image.RGBA
	var err error
	ops := new(op.Ops)
	for i := 0; i < 3; i++ {
		ops.Reset()
		img, err = drawImage(t, 128, ops, f)
		if err != nil {
			t.Error("error rendering:", err)
			return
		}
		// check for a reference image and make sure we are identical.
		if !verifyRef(t, img, 0) {
			name := fmt.Sprintf("%s-%d-bad.png", t.Name(), i)
			if err := saveImage(name, img); err != nil {
				t.Error(err)
			}
		}
		c(result{t: t, img: img})
	}

	if *dumpImages {
		if err := saveImage(t.Name()+".png", img); err != nil {
			t.Error(err)
		}
	}
}

func frame(f func(o *op.Ops), c func(r result)) frameT {
	return frameT{f: f, c: c}
}

type frameT struct {
	f func(o *op.Ops)
	c func(r result)
}

// multiRun is used to run test cases over multiple frames, typically
// to test caching interactions.
func multiRun(t *testing.T, frames ...frameT) {
	// draw a few times and check that it is correct each time, to
	// ensure any caching effects still generate the correct images.
	var img *image.RGBA
	var err error
	sz := image.Point{X: 128, Y: 128}
	w := newWindow(t, sz.X, sz.Y)
	ops := new(op.Ops)
	for i := range frames {
		ops.Reset()
		frames[i].f(ops)
		if err := w.Frame(ops); err != nil {
			t.Errorf("rendering failed: %v", err)
			continue
		}
		img, err = w.Screenshot()
		if err != nil {
			t.Errorf("screenshot failed: %v", err)
			continue
		}
		// Check for a reference image and make sure they are identical.
		ok := verifyRef(t, img, i)
		if frames[i].c != nil {
			frames[i].c(result{t: t, img: img})
		}
		if *dumpImages || !ok {
			name := t.Name() + ".png"
			if i != 0 {
				name = t.Name() + "_" + strconv.Itoa(i) + ".png"
			}
			if err := saveImage(name, img); err != nil {
				t.Error(err)
			}
		}
	}

}

func verifyRef(t *testing.T, img *image.RGBA, frame int) (ok bool) {
	// ensure identical to ref data
	path := filepath.Join("refs", t.Name()+".png")
	if frame != 0 {
		path = filepath.Join("refs", t.Name()+"_"+strconv.Itoa(frame)+".png")
	}
	b, err := ioutil.ReadFile(path)
	if err != nil {
		t.Error("could not open ref:", err)
		return
	}
	r, err := png.Decode(bytes.NewReader(b))
	if err != nil {
		t.Error("could not decode ref:", err)
		return
	}
	if img.Bounds() != r.Bounds() {
		t.Errorf("reference image is %v, expected %v", r.Bounds(), img.Bounds())
		return false
	}
	var ref *image.RGBA
	switch r := r.(type) {
	case *image.RGBA:
		ref = r
	case *image.NRGBA:
		ref = image.NewRGBA(r.Bounds())
		bnd := r.Bounds()
		for x := bnd.Min.X; x < bnd.Max.X; x++ {
			for y := bnd.Min.Y; y < bnd.Max.Y; y++ {
				ref.SetRGBA(x, y, f32color.NRGBAToRGBA(r.NRGBAAt(x, y)))
			}
		}
	default:
		t.Fatalf("reference image is a %T, expected *image.NRGBA or *image.RGBA", r)
	}
	bnd := img.Bounds()
	for x := bnd.Min.X; x < bnd.Max.X; x++ {
		for y := bnd.Min.Y; y < bnd.Max.Y; y++ {
			exp := ref.RGBAAt(x, y)
			got := img.RGBAAt(x, y)
			if !colorsClose(exp, got) {
				t.Error("not equal to ref at", x, y, " ", got, exp)
				return false
			}
		}
	}
	return true
}

func colorsClose(c1, c2 color.RGBA) bool {
	const delta = 0.01 // magic value obtained from experimentation.
	return yiqEqApprox(c1, c2, delta)
}

// yiqEqApprox compares the colors of 2 pixels, in the NTSC YIQ color space,
// as described in:
//
//   Measuring perceived color difference using YIQ NTSC
//   transmission color space in mobile applications.
//   Yuriy Kotsarenko, Fernando Ramos.
//
// An electronic version is available at:
//
// - http://www.progmat.uaem.mx:8080/artVol2Num2/Articulo3Vol2Num2.pdf
func yiqEqApprox(c1, c2 color.RGBA, d2 float64) bool {
	const max = 35215.0 // difference between 2 maximally different pixels.

	var (
		r1 = float64(c1.R)
		g1 = float64(c1.G)
		b1 = float64(c1.B)

		r2 = float64(c2.R)
		g2 = float64(c2.G)
		b2 = float64(c2.B)

		y1 = r1*0.29889531 + g1*0.58662247 + b1*0.11448223
		i1 = r1*0.59597799 - g1*0.27417610 - b1*0.32180189
		q1 = r1*0.21147017 - g1*0.52261711 + b1*0.31114694

		y2 = r2*0.29889531 + g2*0.58662247 + b2*0.11448223
		i2 = r2*0.59597799 - g2*0.27417610 - b2*0.32180189
		q2 = r2*0.21147017 - g2*0.52261711 + b2*0.31114694

		y = y1 - y2
		i = i1 - i2
		q = q1 - q2

		diff = 0.5053*y*y + 0.299*i*i + 0.1957*q*q
	)
	return diff <= max*d2
}

func (r result) expect(x, y int, col color.RGBA) {
	r.t.Helper()
	if r.img == nil {
		return
	}
	c := r.img.RGBAAt(x, y)
	if !colorsClose(c, col) {
		r.t.Error("expected ", col, " at ", "(", x, ",", y, ") but got ", c)
	}
}

type result struct {
	t   *testing.T
	img *image.RGBA
}

func saveImage(file string, img *image.RGBA) error {
	// Only NRGBA images are losslessly encoded by png.Encode.
	nrgba := image.NewNRGBA(img.Bounds())
	bnd := img.Bounds()
	for x := bnd.Min.X; x < bnd.Max.X; x++ {
		for y := bnd.Min.Y; y < bnd.Max.Y; y++ {
			nrgba.SetNRGBA(x, y, f32color.RGBAToNRGBA(img.RGBAAt(x, y)))
		}
	}
	var buf bytes.Buffer
	if err := png.Encode(&buf, nrgba); err != nil {
		return err
	}
	return ioutil.WriteFile(file, buf.Bytes(), 0666)
}

func newWindow(t testing.TB, width, height int) *headless.Window {
	w, err := headless.NewWindow(width, height)
	if err != nil {
		t.Skipf("failed to create headless window, skipping: %v", err)
	}
	t.Cleanup(w.Release)
	return w
}

func scale(sx, sy float32) op.TransformOp {
	return op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(sx, sy)))
}